Electric-circuit controller.



H. W. LEONARD. ELECTRIC CIRCUIT CONTROLLER. APPLIOATION FILED APR. 6,1906.

914,356. Patented Mar. 2, 1909.

' P J J N c I g a c d a Q 0 6 I O! 0 M P J J N 1 a" I B YINVENTOR Irm/my current.

HARRY WARD LEONARD, OF BRONXVILLE, NEW YORKv ELECTRIC-CIRCUIT GONTBOLLER.

No. 914,356. Original application filed November 30, 1 901,

Specification 0: Letters Patent.

Serial No. 237,653. Divided. and this application filed. April 6, 1906.

' Serial No. 310,200. ,7

Patented March 2, 1909.

To all whom it may concern:

Be it known that I, HARRY WARD LEON- ARD, a citizen of the UnitedStates, residing at Bronxville, in the county ofWestchester and State ofNew York, have invented cer tain new and useful Improvements inElectric-Circuit Controllers, of which the following is a full, clear,and exact specification.

This application is a division of my pending application filed November30, 1901, Serial No.- 84,188,- renewed December 20, 1904, Serial No.237,653, granted April 10, 1906, Patent No. 817,719, and relatesgenerally to controlling switches and has a articular application tomotor starting r eostats, or rheostats employed with electric motors orotheargr ectrical translating devices, in which the resistance isemployed not for regulating the energy supplied to the motor or othertranslating device, but mainly for gradually raising the energy at theterminals 'of the translating device to the full electromotive force.

My invention is also of importance where regulating resistances are usedand to prevent their improper operation. v

I have. found inpractice that such rheostats are fre uently damaged byholding or permitting t 1e contact lever to remain on the initial orstarting contact or contacts near the same with all the resistance ofthe rheostat or a considerable portion thereof in circuit. I have alsofound that operators frequently close the circuit at the initial orstarting contact of the nheostat and then return the lever to the idleposition, thus drawing an are at the initial contact. This also damagesthe rheostat. I have also found that operators sometimes close the maincircuit when the resistance controlling device, which 'might he used asregulator, is in an intermediate position. This of course allows anexcessive and damaging flow of The main object of my invention is todevise a starting rheostat or controller, or to provide the resent typeof rheostat with a controlling evice, which will prevent this im roperhandling of such. rheostats.

though of importance in connection with hand controlled rh'eostats, myinvention is also of advantage in connection with automatically operatedrh'costats.

The full torque current is the current which the motor takes indeveloping its full rated horsegip'ower. Instarting any motor, itbecomes necessary to produce a torque larger than thatdue to the fulltor ue current because the motor and the load rave to be accelerated,and during the period of acceleration, a larger current will he requiredthan that necessary after the motor has been accelerated to full speed.In the manufacture of motor starting rheostats, it is conimon practiceto have such a resistance in the'rheosta-t that the current which willflow when the motor is at rest and the first contact is made at therheostat, will be fifty per cent. larger than the current taken by themotor when producing its normal full torque. In otherwords, thisstarting accelerating current is fifty per cent. larger than the fulltorque current, that is, it is one hundred and fifty per cent. of thefull torque current;

In order to prevent the burning at the ini tial contact of the rheostat,due to the closing of the circuit upon insufficient surface, or due tothe backward movement of the contact lever after making the firstcontact, which results in the formation of an arc due to the 'fullelcctromotive force and one hundred and ii'fty per cent. of the fulltorque current (when the motor has no counter electromotive force), therheostat should be provided with an auxiliary switch, by which thecircuit is quickly closed upon an ample surface and which switch willopen the circuit with. a snap-action when the contact lever is returnedto the initial position. This auxiliary switch should be beyond directhand control in 0 ening and may be mechanically or electrical ycontrolled by tho rheostat contact lover or controlling switch.

In my original application, I have dis closed two forms of my inventionin which the auxiliary switch ismechanically controlled. The .rcsentapplication relates more particular Y to forms in which the control ofthe auxiliary switch is by electrical means. 1

My invention includes various other improvements and advantages whichwill be understood from the followingdcscription and accompanyingdrawings.

Inthe accompanying drawings, Fi ure 1 is a diagrammatic View of one form0- m invention' and Fi 2 is a similar view 0 an other form of m'*invention.

Referring to 1g. 1, there 18 mounted on a a, to which the sectionssuitable base (not shown) a series of contacts of the resistance a areconnected. This resistance, it will be understood is arranged in anysuitable manner beneath the base or within a casing, and the sections ofresistance will be insulated from each other and in some instancesproand in this instance is started by solenoids O and 0 whose cores areconnected to the arms of the hammer, and d is the spring for throwingthe hammer after it passes the center of equilibrium, although in thisarrangement the spring might be dispensed with, since the movement ofthe cores will be very rapid and move with increasing s eed. The circuitconnections are from con uctor P to switch C, to lever B, resistance aand motor M to the conductor N, the field of M being in shunt from leverB around the resistance and motor armature. Coils O and O are. connectedin shunt relation between contacts 0 and 0 and conductors P and N.Contacts 0 and 0 are located adjacent to the first and second rheostatcontacts a respectively, so that in the initial position lever B willbridge the first contact a and contact 0, and in the second positioncontact 0 and the second contact a will be bridged. The effect of this,is to connect either coil 0 or O in circuit and as shown coilO is incircuit and its core is drawn down and hammer D is tilted to the rightclosing switch C. If lever B is returned to its initial position, coil 0will be out out and coil 0 cut in, thus actuating the core of the latterto throw the hammer to the left and open switch C. When lever B is movedto its final position, both coils will be cut out of circuit and springd will hold switch C in po sition. 'It is thus apparent that the maincircuit will be completed, and that the main, current flow will beinterrupted at the auxiliarv switchjC, and the sparking which wouldotherwise take place at the resistance contacts is avoided. Amodification of this arrangement is shown in Fig. 2. Here only one coil0! is employed, and this coilis connected between conductor P and acontact 0 with which the insulatedshort arm I) of lever B makes contactwhen in contact with any of the rheostat contacts a from the-second tothe'fmal contacts, but not when in' contact with" the initial contact.Switch C (shown as a brush switch) is provided with a rod 2 which breaksthe on carbon con- 0 and stirrup 2 tacts z. This switch is mounted on avertically sliding rod 2 provided at its upper end with a stirrup 2?within which works a foot 0 securedto the lower end of rod 0 projectingfrom the core or plunger of coil 0 The vertically sliding rods 2 and 0work in suitable guides, and the lower end of rod 2 is rectangular andworks in a correspondingly sha ed bearing to hold switch C in alinementwit its stationary contacts.

As shown in Fig. 2, the rheostat lever B is in its second position, andthe circuit to coil 0 is closed and. its core is drawn up and switch Cisclosed. If now the operator returns leverB to the initial position, coil0 will become "demagnetized and its plunger will drop striking a blow tothe stirrup, the force of which and. the tension of the brush switch,will drive theswitch downward and 0 en the circuit to the rheostat andmotor. V hen the lever B is moved forward, closing the circuit again atcontact 0 the plunger of coil 0 will rise, and through the engagement offoot switch C will be closed.

It will be noted that I have indicated a motorM in the drawings having ashunt field winding, and that the supply cricuit to both the armatureand shunt winding is opened by means of the automatic switch in the maincircuit. 'Also, that when the circuit is opened,

the armature and field are closed on them-' selves, giving aclosedcircuit for the field discharge.

It is evident that my invention may be embodied in various forms ofconstruction and that I am not limited in the scope thereof except asindicated in the following claims.

Having thus described my invention, Tdeclare that what I claim as newand desire to secure by Letters Patent, is,-- I

1 The combination of a rheostat, a switch, an electro-magnetic actuatingdevice there for, and means whereby said switch is closed and opened bythe forward and backward movement of the movable element of saidrheostat at the initial'positions.

2. The combination of a hand operated electric switch, a second switchin series therewith, means for automatically moving said second switchto the closed. or to the openposition com rising electrical controllingmeans operate by the movement of said hand 0 erated switch.

31' The combination of a rheostat having a movable element forcontrolling the resistance, a switch in series therewith, means formoving-said switch to the closed or open 0- sition, and electricalcontact means control by the position of said element for contFollingsaid switch moving means.

4. The combination with a rheostat having a movable element forcontrolling the resistance, of a switch in circuit therewith, anelectro-magnetic, actuating device for said switch, and means wherebysaid switch is exce s limiting positions. Ii

' 5. The combination of a motor riaeostat having a movable element forcontrolling the resistance, a SWl-tCll in series therewlts, means formoving said switch to the closed or open Cir positions, and electricalcontact means controlled bythe position of sa d-element for causing saidswitch moving means to actuate 1 said switch and complete the circuitand to cause the opening of said switch to interrupt the current flow..

6. The combination of a motor rheostat, a switch for closing thecircuit, a control magnet governing its closure, and means forcontrolling the circuit connections of said magnet dependent upon thereturn of the resistance controlling element of said rheostat t theinitial position. I p

7.. The combination of a motor rlieost-at having a movable element forcontrolling the resistance, a circuit breaker, a contact engaged by themovement of said element, a coil in circuit with said contact andcontrol ling the closing of said circuit breaker, and circuitconnections wl...ere.by said coil is deenergized after said circuitbreaker i'as been closed, j i

S. The combination of a motor rl eostat having a movable element'forcontrolling the resistance, a circuit breaker, a contact engaged by themovement of said element, a

j l l coil in circuit wit said contact and control I ling the closing ofsaid circuit breaker, and

means w? ereby after saidcircuit breaker as been closed tle circuitofsaid coil may be opened wit? out affecting said circuit breaker.

9. The combination of a supply circuit, an electric motor, a switch forconnecting and disconnecting the motor armature to and j from the supplycircuit, electromagnetic? means for actuating said switch to connect anddisconnect said motor armature to and from the supply circuit, and meanswhereby said electromagnetic means is automatically deenergiz'ed duringnormal operation of said motor.

10. The combination of a translating device, a controlling switch, anelectromagnetic win ding for effecting the closure of said switch whensaid winding is energized,

means for holding said switch closed indewndently of said windingafterthe switch has been moved to closed position, and means whereby thecurrent in said winding is reduced after the closure ofsaid switch.

11. The combination of-a resistance having a movable element for Varyingthe resistance, a switch, a coil controlled by the movement of saidelement for contitolling the closure of said switch, and a second coilcontrolled by the movement of said element for controlling the openingof said switch.

12. The combination of a resistance-having a movable element for varyingthe resistance, a switch, electromagnetic means for closing said switch,means controlled by the movement of said element for interrupting thecircuit otsaidelectromagnetic means, and auxiliary means for holdingsaid switch closed.

' 13. The combination of an electric motor, an annature resistance, aswitch in series with said resistance, a coil for closing said switchautomatically, a second coil for automatically opening said switch, andmeans for insuring the automatic closure of said switch only when aprotective amount of resistance is in series with the motor armature.

14. The combination of an electric motor, a switch in series with themotor armature, two actuating coils for controlling the automaticmovement of said switch, one of said coils being energized during theclosing of said switch and the other of said coils being energizedduring the opening of said switch, and additional means for maintainingsaid switch closed.

15. The combination of a supply circuit, an electric motor, an automaticswitch in series with the motor armature, a coil for conand connectionswhereby said coil is connected in series with the motor armature acrossthe supply circuit during the closing period of said switch whereby saidcoil is subjected to the electromotive force of the supply circuit lessany counter electromotive force of the motor armature.

16. The combination of an electric motor, an armature controllingrheostat, an electromagnetically controlled automatic switch, means forcontrolling .the closing movement of said switch by the movement ofthejmo-vable element of said rheostat when moved in the resistanceinserting direction, and means controlled by the movement of saidelement for causing the automatic opening of said switch. y

17. The combination of a supply circuit,

an electrlc motor, an armature resistance, a

sistance, a constant electromotive force supply circuit, anelectromagnetic winding, a switch controlled by said windingmlrd means II said supply circuit,

automatically closable through the agency of for connecting said windingin series with means whereby said first named switch is connected inshunt to said winding.

21. The combination of a constant electromotive force supply circuit, anelectric motor, a controlling resistance therefor, an electromagneticwinding, a switch controlled by said winding and adapted to be connectedin series with the armature of said motor and in shunt with saidwinding, and means for said resistconnecting the motor armature,

across the ance, and said winding in series supply circuit.

22. The combination of a constant electromotive force supply circuit, anelectric motor, a controlling resistance therefor, an

electromagnetic winding, a switch whose closing movement is controlledby said winding and which switch is adapted to be connected in serieswith the motor armature and said resistance and in shunt winding, andmeans for connecting said motor armature, said resistance, and saidwind- ?ing in series across the supply circuit.

23. The combination of a constant electromotive force supply circuit, anelectric motor, an armature resistance, a manually operated switch, anelectromagnetic winding, connections for connectin the motor armature,said resistance, sai switch, and said winding in series in a branchcircuit across an automatic switch said winding, and connection wherebysaid automatic switch, the motor armature, and said resistance areconnected in series with each other and whereby said automatic switch isconnected-in shunt with said wind- 1n a supply circuit of constantelectromotive force, a manually operated rheostat, a switch, said switchand rheostat being in series with each other and with the motor armatureacross said circuit, and electrical means controlled by the movement ofthe movable element of the rheostat for controlling the closing andopening of said switch to establish and break the current through themotor armature. v

25. The'combination of an electric motor having a field windingenergized independently of its armature current, a manually operatedrheostat for controlling the motor armature, a switch for carrying boththe ;-through said field winding,

means controlled by with said g 24. The combination of an electricmotor,

motor armature current and the current and electrical the movement ofthe movable element of said rheostat for causing the automatic closingand opening of said switch.

26. The combination of a supply circuit of an electric constant'ielectromotive force, motor, ai armature controlling rheostat, saidrheostat, the motor armature and a field winding oftthe motor beinconnected in a closed circuit-,a magnetically moved switch for makingand breaking connection between said closed circuit and the supplycircuit, and electrical means dependent .upon the movement of themovable element of the rheostat for controlling the opening movement ofsaid switch.

27. The combination of a rheostat having a movable element forcontrolling the resistance, an automatic switch in series therewith,and: electrical-means operated by the movement of said element forcontrolling the automatic closing and automatic opening of said switch.

2-8. The combination with a sup ly circuit, of a resistance having amanual y movable element for varying said resistance,. a switch inseries therewith, and electrical means for controlling the closing andopening of said switch, said means being controlled by said movableelement whereby said switch is closed when said element is manuallymoved in a direction to reduce resistance and is o ened when saidelement is moved in a direction to increase resistance.

2-9. The combination of a resistance having a manually movable elementadapted to vary the resistance, a switch for controlling the circuit ofsaid resistance, and electricmeans for controlling the automatic closingand automatic opening of said switch, said means being controlled by themovement of said movable element.

30. The combination el a motor, a rheostat for said motor having amanually movable resistance varying element, an automatic.electromagnetic switch, and electric means for causing the manualmovement of said element to control the movement of said switch in twodirections at the starting position. a

'31.'The combination of a motor, a rheostat for said motor having amovable 're sistance varying element, means for causing an auxiliaryelectrical contact to be made by the movement of said element to. acertain osition and to be broken'by its movement in a direction toinsert resistance, an electroresponsive winding energized independentlyof the motor operating current and the current in which is affected bythe making and breaking of said contact, and aswitch in series with themotor armature controlled by said electroresponsive winding.

the movement of saidielement in a direction.

to reduce said resistance and for. controlling the breaking of saidcontact; by its movement in theopposite direction, an electrothe currentin. which is responsive windln affected by thev ma ring and breakingofisaid contact, and a switch the closingmovement of which iscontrolledby said winding.

33. The combination-of an electric motor, a controllin rheostat havin amanually controlled e ement, a switch 1n series with said rheostat, andvelectrical means controlled by said element when moved in a direction toinsert and in a direction to cut out resistance for causing the openingand closing of said switch independently of the rate of movement of saidelement.

34. The combination with a rheostat and a movable element for varyingthe resistance, of a switch for controlling the circuit of saidrheostat, and electrical means operated by said element when moved in aforward and backward. direction for respectively controllin the closingand opening movement of saic switch.

35. The combination of a resistance controlling movable element, aswitch in series therewith, and electrical means operated by themovement of said resistance controlling element for controlling both theautomatic closing and automatic opening of said switch.

36. The combination of a'rheostat having a manually movable element forvarying the resistance, a switch for controlling the circuit to saidrheostat, and electrical means operated by said element for controllingboth the closing and opening movement of" said switch when said elementis in position to insert substantially all of said resistance.

37. The combination of an electromotive force producing device, anautomatic switch Whose automatic movement is dependent upon a currentother than the current passin through said device, a rheostatic movab eelement in series with said switch, and a manuall controlled auxiliarycontact device functionally-related to said element for controlling theautomatic closing and automatic o ening of said switch.

38. he combination of a rheostat having a movable element for varyingthe resistance, a switch in series therewith, restraining means forholding said switch in closed position, and means controlled by saidelement (in when substantially all of the resistance is in circuitforelectrically closing said switch.

39. The combination of a rheostat having a movable element for varyingthe resistance, anv electromagnetic switch in series therewith,restraining means for holding said lectively ener izing said coils.

pendently of the motor current, and a contact at or near the initialposition of said element for energizingsaid coil.

41'.. The combination of'a resist'ancecontrolli'n current carryinmovable element, said element being adapted to vary the amountofresistance in circuit but not adapted to interrupt the flow ofcurrent, a switch in series with said element adapted to open and closethe circuit, and electromagnetic means functionally related to saidelement for controlling the automatic closing and automatic opening ofsaid switch.

42. The combination of an automatic switch corn rising two actuatingcoils, a circuit contro ling movable element in series with said switch,and means dependent upon the movement of said element for se- 43. In cominatlon, a motor controller, a switch, and means'for automaticallyclosing and opening said switch, said means comprising a magnet foropening said switch to control the motor circuit, and connectionswhereby said magnet is ener ized only when the controller is moved bacward to a cer-.

ment, and means whereby said magnet isj energized only when thecontroller in its backward movement reaches a predetermined osition. 4

45. n combination, a controller for an electric motor, a switch throughwhich the motor current is supplied when the controller is in apredetermined position, and means for automatically closing andautomatically opening said switch comprising a magnet for opening saidswitch, and means whereby said'magnet is energized only when thecontroller in its backward movement reaches a predetermined position. 7

46. The combination of a rheostat having a movable element forcontrollin the resistance, an electromagnetic switc in series therewith,manually controlled. auxiliary electric contact means functionallyrelated to said element for controlling the automatic movement of saidelement to a protective position.-

47. The combination of an electric motor, an armature controllingrheostat, an electromagnetically controlled automatic switch, means forcontrolling the closing movement of said switch by the movement of themovable element of said rheostat when moved in the resistance insertingdirection, and auxiliary electric contact means functionally related tosaid element for causing the automatic opening of said switch.

48. The combination of a motor, -a motor controller having a movableelement manually movable in both directions, a movable circuit closingelement, means for automatically moving said element to close itscircuit, said means comprising a magnet for controlling the closingmovement of said element, and means whereby said magnet is energized tocause the closure of said element only when the controller in itsbackward movement reaches a redetermined osition, the connection of saidclosing coil eing such that said coil is energized inde pendently of themotor armature current.

In testimonywhereof, I affix my signature-

